The present invention relates to extraction of tobacco components, and in particular to a process for providing a tobacco extract.
Popular smoking articles, such as cigarettes, have a substantially cylindrical rod shaped structure and include a charge of smokable material, such as shreds of strands of tobacco material (i.e., in cut filler form), surrounded by a paper wrapper, thereby forming a tobacco rod. It has become desirable to manufacture a cigarette having a cylindrical filter element aligned in an end-to-end relationship with the tobacco rod. Typically, a filter element includes cellulose acetate tow circumscribed by plug wrap, and is attached to the tobacco rod using a circumscribing tipping material. Many cigarettes include processed tobacco materials and/or tobacco extracts in order to provide certain flavorful characteristics to those cigarettes.
Many types of smoking products and improved smoking articles have been proposed through the years as improvements upon, or as alternatives to, the popular smoking articles. Recently, U.S. Pat. Nos. 4,708,151 to Shelar; 4,714,082 to Banerjee et al; 4,756,318 to Clearman et al; 4,793,365 to Sensabaugh, Jr. et al; 4,827,950 Banerjee et al; 4,893,639 to White; 4,917,128 to Clearman et al; 4,928,714 to Shannon; and 4,938,238 to Barnes et al, and propose cigarettes and pipes which comprise a fuel element, an aerosol generating means physically separate from the fuel element, and a separate mouth-end piece. Such types of smoking articles are capable of providing natural tobacco flavors to the smoker thereof by heating without necessarily burning tobacco in various forms.
Natural flavors and particularly natural tobacco flavors are important components of smoking articles and provide taste and aroma to the smoking article. Thus, improved processes for providing natural flavorful and aromatic substances as well as flavorful and aromatic forms of tobacco are desirable. As a result, there has been interest in the isolation of various natural flavorful and aromatic components from natural materials such as food products (e.g., fruits), grains and tobacco. For example, the isolation of the essence of nectarines is proposed by Takeoka et al in a journal article entitled "Nectarines Volatiles: Vacuum Steam Distillation versus Headspace Sampling" in J. Agric Food Chem. vol. 36, pp 553-560. The extraction of hop oil is proposed by Pickett et al in a journal article entitled "Recent Developments in Low Temperature Steam Distillation of Hop Oil" in J. Inst. Brew, vol. 83, pp 302-304, (1977).
There has also been interest in extracting particular components from tobacco. For example, various processes for producing and using tobacco extracts, aroma oils and concentrates are proposed in U.S. Pat. Nos. 3,136,321 to Davis; 3,316,919 to Green; 3,424,171 to Rooker; 4,421,126 to Gellatly 4,506,682 to Mueller and 4,967,771 to Fagg et al., 4,986,286 to Roberts et al. and European Patent Nos. 38,831 to Clapp et al. and 326,370 to Fagg. Such materials conveniently can be applied to tobacco laminae, reconstituted tobacco sheet and other engineered tobacco materials, cigarette filters and other substrates, and the like.
It would be highly desirable to provide a tobacco extract while avoiding the necessity of subjecting a tobacco material or tobacco extract to conditions, for example, highly elevated temperatures above about 85.degree. C., which can alter to some degree the chemical character of the tobacco material and tobacco extract, and sometimes can cause the loss of the volatile flavorful and aromatic components thereof.